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US4289038A - Fail-safe attachment for an actuator - Google Patents

Fail-safe attachment for an actuator Download PDF

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Publication number
US4289038A
US4289038A US06/022,056 US2205679A US4289038A US 4289038 A US4289038 A US 4289038A US 2205679 A US2205679 A US 2205679A US 4289038 A US4289038 A US 4289038A
Authority
US
United States
Prior art keywords
actuator
cam plate
fail
safe
spring
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US06/022,056
Other languages
English (en)
Inventor
Donald L. Hore
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Rotork PLC
Original Assignee
Rotork PLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Rotork PLC filed Critical Rotork PLC
Application granted granted Critical
Publication of US4289038A publication Critical patent/US4289038A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03G—SPRING, WEIGHT, INERTIA OR LIKE MOTORS; MECHANICAL-POWER PRODUCING DEVICES OR MECHANISMS, NOT OTHERWISE PROVIDED FOR OR USING ENERGY SOURCES NOT OTHERWISE PROVIDED FOR
    • F03G1/00—Spring motors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03G—SPRING, WEIGHT, INERTIA OR LIKE MOTORS; MECHANICAL-POWER PRODUCING DEVICES OR MECHANISMS, NOT OTHERWISE PROVIDED FOR OR USING ENERGY SOURCES NOT OTHERWISE PROVIDED FOR
    • F03G1/00—Spring motors
    • F03G1/02—Spring motors characterised by shape or material of spring, e.g. helical, spiral, coil
    • F03G1/022—Spring motors characterised by shape or material of spring, e.g. helical, spiral, coil using spiral springs
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K17/00—Safety valves; Equalising valves, e.g. pressure relief valves
    • F16K17/20—Excess-flow valves
    • F16K17/22—Excess-flow valves actuated by the difference of pressure between two places in the flow line
    • F16K17/32—Excess-flow valves actuated by the difference of pressure between two places in the flow line acting on a servo-mechanism or on a catch-releasing mechanism
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16K—VALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K31/00—Actuating devices; Operating means; Releasing devices
    • F16K31/44—Mechanical actuating means
    • F16K31/56—Mechanical actuating means without stable intermediate position, e.g. with snap action
    • F16K31/563—Mechanical actuating means without stable intermediate position, e.g. with snap action for rotating or pivoting valves
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T74/00—Machine element or mechanism
    • Y10T74/11—Tripping mechanism

Definitions

  • This invention relates to a fail-safe attachment for actuators, and more particularly but not exclusively, to such an attachment for electrically operated actuators which produce a predetermined angular movement of an output member for operating a semi-rotary device to be actuated, for example a quarter-turn valve such as a butterfly or ball valve.
  • a quarter-turn valve such as a butterfly or ball valve.
  • One such electrically operated quarter-turn actuator of this kind is described and claimed in our co-pending appln. No. 862,092, now U.S. Pat. No. 4,177,395 and the fail-safe attachment of the present invention has particular use with such an actuator in that it provides for emergency operation of the actuator to a desired fail-safe position in the event of, or during power failure without in any way affecting the normal operation of the actuator.
  • the energy store is most conveniently a spring and generally most powered valves using spring energy are controlled by a single-acting actuator against a return spring.
  • the spring must be powerful enough in its most extended condition to provide the required force at the end of valve travel, while the power actuator must be powerful enough to overcome the spring force, which increases as the spring is compressed, as well as providing the force needed to operate the valve.
  • the main object therefore, of this invention is to provide the stored energy capability of a spring for emergency operation of a valve normally powered by an electrically operated double-acting actuator without reducing the power available to operate the valve from a given actuator, and eliminating the problem of continuous power consumption while the valve is in its normal, as opposed to emergency position.
  • An additional object of the invention is to prevent unnecessary discharge of the spring on power failure if the valve is already in the ⁇ safe ⁇ position.
  • the invention is more particularly applicable to quarter-turn valve actuators and in one preferred embodiment the emergency power is supplied by a spring which is manually compressed until the required energy for the emergency stroke is stored.
  • the spring drives a rotatable fail-safe cam plate coupling which is normally held against movement to retain the spring charge by a latch under the control of an electro-magnet.
  • the electro-magnet can be energized either by the actuator power supply voltage or by a separate ⁇ safe ⁇ supply, e.g. from a d.c. battery.
  • the arrangement is such that the latch retains the spring charge so long as the electro-magnet remains energised.
  • the electro-magnet is de-energised, e.g.
  • a small release spring forces the armature away from the electro-magnet which allows the main spring to overcome the latch and to rotate the fail-safe cam plate coupling.
  • the fail-safe cam plate coupling is drivably connected with the switch cam plate by means of a coupling incorporating adequate backlash, e.g. 110°.
  • the arrangement enables the actuator to operate normally in both directions of movement by electrical power in response to the appropriate open and close signals even though the spring is charged. Only when the latch is released can the spring override the actuator and force the valve to its fail-safe position by rotation of the switch cam plate.
  • FIG. 1 is a sectional side elevation of the fail-safe attachment as fitted to the upper end of the rotor shaft of the actuator, and
  • FIG. 2 is a section on the line II--II of FIG. 1.
  • FIG. 1 the drawing shows the upper compartment 10 of the actuator 11 and which contains the fail-safe attachment 12 of the invention.
  • switch cam plate 14 is pinned at 16 to shaft 13 which is mounted on the valve at its lower end and the function of these two plates 14 and 15 is described in the co-pending appln. No. 862,092, now U.S. Pat. No. 4,177,395.
  • a switch 17 is shown in FIG. 1 as indicative of the various switches actuated by switch cam plate 14 in the control of the actuator.
  • the switch cam plate 14 is shown in dotted lines in FIG. 2 for clarity.
  • the fail-safe attachment 12 includes a fail-safe cam plate coupling 18 which is shown in full lines in FIG. 2 and which has on its under-surface diametrically positioned abutments 18A and 18B which are adapted to engage similar raised abutments 14A and 14B on switch cam plate 14 upon rotation of fail-safe cam plate coupling 18 which is freely mounted on the upper end of shaft 13.
  • the angular distance between adjacent side edges of the abutments 18A and 18B is such that the backlash provided for the abutments 14A and 14B is more than 110° thus enabling the switch cam plate 14 to rotate fully during normal operation of the actuator without being affected by the fail-safe cam plate coupling 18.
  • the shaft 13 as viewed in FIG. 2 rotates anti-clockwise to its valve open position and the fail-safe attachment 12 has been fitted to the shaft 13 to rotate the shaft clockwise during emergency operation so as to close the valve.
  • the cam plate coupling 18 is restrained during normal operation of the actuator from clockwise rotation as viewed in FIG. 2 by a latch pawl 19 which as shown is engaged by an abutment 20 on the cam plate 18.
  • the latch pawl 19 is pivotally mounted at 21 on a latch lever 22 which itself pivots about a fixed pin 23 mounted on the support chassis 24 which is carried by two of the four support pillars 25 attached to the actuator housing.
  • the clockwise torque applied by cam plate coupling 18 to lever 22 via pawl 19 tends to turn the lever 22 anti-clockwise about its pivot pin 23.
  • This movement is restrained by a roller 26 on the end of lever 22 and which engages a ramp 27 on a magnet lever 28 which is pivotted about a fixed pin 29 mounted on the chassis 24.
  • the anti-clockwise pressure from roller 26 on ramp 27 tends to turn the magnet lever 28 clockwise but it is restrained by a fixed electro-magnet 30 so long as its coil 31 is energised, the armature 32 of the electro-magnet being mounted on the lever 28.
  • the electro-magnet 30 is connected to an electrical supply (not shown) so that the electro-magnet will become de-energised upon disconnection, e.g. on power failure or a deliberate emergency trip.
  • Clockwise rotation of the fail-safe cam plate coupling 18 is in response to the stored energy of a spiral spring 33 which is manually set and which as shown in FIG. 1 is located in compartment 10 above the cam plate coupling 18.
  • the spring 33 is preloaded to the requisite minimum (spring extended) torque on assembly when its outer end is secured to wall 34 of the supporting housing 35 which is mounted on a chassis 36 carried by the four pillars 25 attached to the actuator housing.
  • the inner end 37 of the spring 33 is retained by an arbor 38 which is turned clockwise by the spring 33.
  • the cam plate coupling 18 is coupled directly with the arbor 38 by drive dogs 39 and the arbor 38 can be turned manually to set the spring 33 by an external knob 40 retained rotatably in the top cover 41 of the actuator and which has a drive pin 42 engaging a key slot 43 in the arbor 38.
  • the fail-safe attachment 12 can be set by turning the knob 40 anti-clockwise which sets the spring 33 and also rotates cam plate coupling 18 anti-clockwise.
  • the attachment 12 is set for operation when the fail-safe cam plate coupling 18 is latched as shown in FIG. 2 by engagement of abutment 20 with the latch pawl 19.
  • the pawl 19 is free to turn clockwise about pin 21 during the anti-clockwise rotation of cam plate coupling 18 against a spring 44 so as to permit overtravel of the cam plate coupling 18, the pawl 19 then springing back into place against an edge 45 upstanding from latch lever 22.
  • FIG. 2 the actuator is shown at the end of its anti-clockwise direction of travel in which the valve is in its open position.
  • the limit switch cam plate 14 is in the position shown with the abutment 14A, 14B closely adjacent the abutments 18A, 18B on fail-safe cam plate coupling 18.
  • cam plate coupling 18 The clockwise rotation of cam plate coupling 18 is then transmitted by abutments 18A and 14A, and 18B and 14B to switch cam plate 14 which in turn is rotated clockwise to move shaft 13 to its mechanical limit of travel in which the valve is in its closed fail-safe position.
  • the switch cam plate 14 is provided with an inclined surface 46 on abutment 14B and which in the fail-safe position engages an adjustable stop screw 47 on latch lever 22 to reset the lever.
  • the magnet lever 28 is then reset by a tension spring 48 connected to chassis 24.
  • the clockwise rotation of the fail-safe cam plate coupling 18 is also arranged to actuate the switch 49 (FIG. 2) which may be adapted to signal loss of spring charge and also to prevent any further electrical operation of the actuator until the spring 33 is recharged by the anti-clockwise movement of the cam plate coupling 18 as previously described.
  • the fail-safe operation described above will occur in response to disconnection of electro-magnet 30 at any time during the stroke of the actuator.
  • the mechanism therefore includes a mechanical interlock which holds the latch lever 22 in the spring restrained position when the valve is in the safe position irrespective of whether the coil 31 of the electro-magnet 30 is energised or not. This is accomplished by the engagement as already described of the surface 46 on cam 14 with screw 47 on latch lever 22 when the actuator is in its fully clockwise position and which therefore prevents anti-clockwise movement of latch lever 22.
  • the fail-safe attachment 12 also includes means to lock the mechanism out of action while in the spring charged condition. This enables the actuator to function normally for test purposes without a latch coil supply and also allows stock units with a fail-safe attachment to be used for non-fail-safe application if required.
  • This lock-out facility is provided by the mounting of a screw 50 in the chassis 24 and which engages the upstanding edge 51 of the latch lever 22 when screwed-in to prevent spring release. The screw 50 must be withdrawn to put the fail-safe attachment 12 into commission.
  • the invention provides a spring operated fail-safe attachment which is manually set and which is independent of the normal operation of the actuator in either direction of movement.
  • the invention thereby overcomes the disadvantages of previously known fail-safe arrangements as hereinbefore mentioned.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Electrically Driven Valve-Operating Means (AREA)
  • Hydraulic Clutches, Magnetic Clutches, Fluid Clutches, And Fluid Joints (AREA)
  • Mechanically-Actuated Valves (AREA)
  • Magnetically Actuated Valves (AREA)
US06/022,056 1978-04-07 1979-03-19 Fail-safe attachment for an actuator Expired - Lifetime US4289038A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB13758/78 1978-04-07
GB1375878 1978-04-07

Publications (1)

Publication Number Publication Date
US4289038A true US4289038A (en) 1981-09-15

Family

ID=10028825

Family Applications (1)

Application Number Title Priority Date Filing Date
US06/022,056 Expired - Lifetime US4289038A (en) 1978-04-07 1979-03-19 Fail-safe attachment for an actuator

Country Status (5)

Country Link
US (1) US4289038A (de)
JP (1) JPS54161117A (de)
DE (1) DE2911569A1 (de)
FR (1) FR2422094A1 (de)
IT (1) IT1118517B (de)

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4831996A (en) * 1986-07-25 1989-05-23 Cero Larry J Target projecting apparatus
US5915668A (en) * 1998-03-06 1999-06-29 Micro-Trak Systems, Inc. Fail safe valve actuator
US5984260A (en) * 1996-10-15 1999-11-16 Baker Hughes Incorporated Electrically driven actuator with failsafe feature
US6015142A (en) * 1997-09-12 2000-01-18 Johnson Controls, Inc. Spring module for return-to-normal actuator
US6315264B1 (en) 1999-02-05 2001-11-13 Gerald Baker Fast-closing stepping actuator for a valve member
WO2002048590A1 (en) * 2000-12-16 2002-06-20 Eco Electronics Limited Fluid control valves
US20090045365A1 (en) * 2007-08-15 2009-02-19 Woodward Governor Company Fail Safe Mechanism For Valve Using A Cock And Lock Return Spring
RU2543646C2 (ru) * 2010-02-15 2015-03-10 Фюрер Инжиниринг Кг Привод с усилителем для предохранительного клапана с высоким приводным моментом
US8973600B2 (en) 2009-06-09 2015-03-10 Mokveld Valves B. V. Valve
US20150240963A1 (en) * 2012-09-10 2015-08-27 Norbert Lenz Electrical actuator
US9435462B2 (en) 2013-05-22 2016-09-06 Precision Engine Control Corporation Valve with latching return spring
US10401051B2 (en) 2012-07-09 2019-09-03 Amrish Chopra Fail-safe actuating system
US20220251997A1 (en) * 2021-02-10 2022-08-11 Illinois Tool Works Inc. Valve assembly failsafe
WO2022173594A1 (en) * 2021-02-10 2022-08-18 Illinois Tool Works Inc. Valve assembly failsafe
US11698140B2 (en) 2020-06-05 2023-07-11 Illinois Tool Works Inc. Ball valve with multi-angular sealing for coolant control regulator

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2580338B1 (fr) * 1985-04-16 1987-06-05 Guerande Etudes Const Meca Dispositif a accumulation d'energie pour la commande automatique de la manoeuvre d'ensembles mecaniques tels que des trappes ou des vannes
JPS62124376U (de) * 1986-01-30 1987-08-07
JP6120638B2 (ja) * 2013-03-29 2017-04-26 株式会社ケーヒン 電動開閉弁

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1134892A (en) * 1913-10-16 1915-04-06 Maxymilian J Myszkier Valve-operating mechanism.
US1559018A (en) * 1925-05-27 1925-10-27 Frank C Taylor Safety control for fluid-fuel valves
US2568916A (en) * 1946-04-03 1951-09-25 Johan Godefroy Thermostatic device for controlling heating apparatus
US2875616A (en) * 1957-07-19 1959-03-03 Ind Heat Engineering Company Safety cut-off valve
US4113063A (en) * 1976-12-06 1978-09-12 Vapor Corporation Mechanical stored energy positioning actuator

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1070465B (de) * 1959-12-03
US2223292A (en) * 1938-05-25 1940-11-26 Maxon Premix Burner Company Shut-off valve
CH389755A (de) * 1961-07-18 1965-03-31 Landis & Gyr Ag Nullspannungs-Rückstelleinrichtung an einem elektromotorischen Antrieb für ein mechanisches bzw. hydraulisches Stellglied
US3279744A (en) * 1964-03-09 1966-10-18 Clary Corp Valve actuator
GB1367780A (en) * 1971-10-26 1974-09-25 Petroles Cie Francaise Safety devices
US3808895A (en) * 1973-02-09 1974-05-07 J Fitzwater Electric fail-safe actuator

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1134892A (en) * 1913-10-16 1915-04-06 Maxymilian J Myszkier Valve-operating mechanism.
US1559018A (en) * 1925-05-27 1925-10-27 Frank C Taylor Safety control for fluid-fuel valves
US2568916A (en) * 1946-04-03 1951-09-25 Johan Godefroy Thermostatic device for controlling heating apparatus
US2875616A (en) * 1957-07-19 1959-03-03 Ind Heat Engineering Company Safety cut-off valve
US4113063A (en) * 1976-12-06 1978-09-12 Vapor Corporation Mechanical stored energy positioning actuator

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4831996A (en) * 1986-07-25 1989-05-23 Cero Larry J Target projecting apparatus
US5984260A (en) * 1996-10-15 1999-11-16 Baker Hughes Incorporated Electrically driven actuator with failsafe feature
US6015142A (en) * 1997-09-12 2000-01-18 Johnson Controls, Inc. Spring module for return-to-normal actuator
US5915668A (en) * 1998-03-06 1999-06-29 Micro-Trak Systems, Inc. Fail safe valve actuator
US6315264B1 (en) 1999-02-05 2001-11-13 Gerald Baker Fast-closing stepping actuator for a valve member
WO2002048590A1 (en) * 2000-12-16 2002-06-20 Eco Electronics Limited Fluid control valves
DE112008002119T5 (de) 2007-08-15 2010-06-24 Woodward Governor Co., Fort Collins Ausfallsichere Einrichtung für ein Ventil unter Verwendung einer Spann- und Rückstellfeder
US7665714B2 (en) 2007-08-15 2010-02-23 Woodward Governor Company Fail safe mechanism for valve using a cock and lock return spring
US20090045365A1 (en) * 2007-08-15 2009-02-19 Woodward Governor Company Fail Safe Mechanism For Valve Using A Cock And Lock Return Spring
US8973600B2 (en) 2009-06-09 2015-03-10 Mokveld Valves B. V. Valve
RU2543646C2 (ru) * 2010-02-15 2015-03-10 Фюрер Инжиниринг Кг Привод с усилителем для предохранительного клапана с высоким приводным моментом
US10401051B2 (en) 2012-07-09 2019-09-03 Amrish Chopra Fail-safe actuating system
US20150240963A1 (en) * 2012-09-10 2015-08-27 Norbert Lenz Electrical actuator
US9714720B2 (en) * 2012-09-10 2017-07-25 Cameron International Corporation Electrical actuator
US9435462B2 (en) 2013-05-22 2016-09-06 Precision Engine Control Corporation Valve with latching return spring
US11698140B2 (en) 2020-06-05 2023-07-11 Illinois Tool Works Inc. Ball valve with multi-angular sealing for coolant control regulator
US20220251997A1 (en) * 2021-02-10 2022-08-11 Illinois Tool Works Inc. Valve assembly failsafe
WO2022173594A1 (en) * 2021-02-10 2022-08-18 Illinois Tool Works Inc. Valve assembly failsafe
US11913370B2 (en) * 2021-02-10 2024-02-27 Illinois Tool Works Inc. Valve assembly failsafe

Also Published As

Publication number Publication date
IT7967625A0 (it) 1979-03-26
FR2422094A1 (fr) 1979-11-02
JPS54161117A (en) 1979-12-20
DE2911569A1 (de) 1979-10-18
IT1118517B (it) 1986-03-03

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